I am trying to find the triple point of H2O given only the densities of water and ice, the enthalpy of vaporization, and the enthalpy of fusion. I know that I should be able to use some combination of the Clapeyron and Clausius-Clapeyron equations to yield a system of two equations in two unknowns, after which I can use a computational engine to solve the system. However, I am having trouble putting this knowledge to use.
A search on stackexchange brought me to the following question, which provides some answers, but confuses me in new ways:
The answer given shows me that I am on the right track, but I am not sure what the lowercase p with the subscripts of sol-liq and liq-vap represents, and while the answerer points out that T1 and P1 are the triple point temperature and pressure, I am not certain of what the T with no subscript is meant to be. My best guesses so far is that the lowercase p is vapor pressure and that the T with no subscript is the standard temperature for the given phase transition.